Use system's cpu_features library

Remove the copied cpu_featrues.c/h
Use the NDK's cpu_features.a or the one build from android source.
This issue blocked libvpx roll.

BUG=334447
R=andrew@webrtc.org, fischman@webrtc.org, henrike@webrtc.org, wjia@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/8019004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@5492 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/system_wrappers/source/Android.mk b/webrtc/system_wrappers/source/Android.mk
index 6cc7a0b..f48019d 100644
--- a/webrtc/system_wrappers/source/Android.mk
+++ b/webrtc/system_wrappers/source/Android.mk
@@ -17,7 +17,6 @@
 LOCAL_MODULE_TAGS := optional
 LOCAL_CPP_EXTENSION := .cc
 LOCAL_SRC_FILES := \
-    android/cpu-features.c \
     cpu_features_android.c \
     sort.cc \
     aligned_malloc.cc \
@@ -56,6 +55,8 @@
     libdl \
     libstlport
 
+LOCAL_STATIC_LIBRARIES := cpufeatures
+
 ifndef NDK_ROOT
 include external/stlport/libstlport.mk
 endif